FR3132607A1 - Vehicle communication method and device using radars - Google Patents

Abstract

The present invention relates to a communication method and device implemented by a first vehicle (10) carrying a millimeter wave radar system. To this end, information on the positions of second vehicles (11 to 13) obtained via the reception of data transmitted according to a mode of communication of the vehicle-to-vehicle type, called V2V, is compared with information on the positions of third vehicles (11 to 14) obtained from a radar (101) of the first vehicle (10). The result of the comparison makes it possible to select a part of the third vehicles (11, 12, 13). A particular communication beam (110, 120, 130) originating from the radar (101) is generated by spatial filtering to cover each selected vehicle (11, 12, 13) and establish a V2V communication via this particular communication beam. Figure for abstract: Figure 1

Description

Communication method and device for vehicle using radars

The present invention relates to communication methods and devices for vehicles, particularly automobiles. The present invention also relates to a method and a communication device using one or more radars fitted to a vehicle, in particular in the context of V2X type communication(s).

Technology background

Contemporary vehicles carry more and more means of communication which often require specific components (antennas, transmitters, receivers), complicating the electronic architecture of the vehicle and increasing its manufacturing cost.

For example, new technologies are emerging that allow the exchange of information between vehicles and/or between vehicles and the infrastructure that surrounds them, these communication technologies being grouped under the name V2X (from the English “Vehicle to Everything” or in French “Véhicule vers tout”). Thus, new information and communication technologies applied to the field of transport have appeared, such as ITS G5 (from the English “Intelligent Transportation System G5” or in French “Système de transport intelligent G5”) in Europe or DSRC (from the English “Dedicated Short Range Communications” or in French “Communications dedicated to short range”) in the United States of America which are both based on the IEEE 802.11p standard or even technology based on cellular networks called C-V2X (from the English “Cellular – Vehicle to Everything” or in French “Cellulaire – Véhicule vers tout”) which is based on 4G based on LTE (from the English “Long Term Evolution” or in French “Long-term evolution”) or 5G.

V2X communication technologies also use the 5.9 GHz frequency band, which results in a maximum rate of 6 Mbits/s for data communication. Such a maximum throughput may prove insufficient to meet the communications needs of vehicles, particularly in the context of autonomous vehicles.

Summary of the present invention

An object of the present invention is to solve at least one of the problems of the technological background described above.

Another object of the present invention is, for example, to improve communication between vehicles.

According to a first aspect, the present invention relates to a communication method for a first vehicle, the first vehicle carrying a millimeter wave radar system, the method comprising the following steps:

- reception of first information representative of the position of each second vehicle of a set of second vehicles, the first information being transmitted by each second vehicle on a control channel on a first frequency band according to a vehicle-to-vehicle type communication mode , known as V2V;

- detection of a set of third vehicles from second information obtained from a radar of the radar system operating on a second frequency band higher than the first frequency band, the second information being representative of the position of each third vehicle;

- selection of at least part of the set of third vehicles by comparison of the positions of the second vehicles with the positions of the third vehicles, the at least part of the set of third vehicles comprising each third vehicle of the set of third vehicles having as position a position of a second vehicle;
the method further comprising the following step for each third vehicle selected:

- generation, by spatial filtering, of a communication beam specific to each third selected vehicle, each communication beam originating from the radar and spatially covering a single third selected vehicle.

The use of position data received using a V2V communication mode makes it possible to identify which vehicles in the environment of the first vehicle correspond to so-called connected vehicles, that is to say vehicles configured to communicate with the first vehicle. via a V2V wireless connection.

The identification of these connected vehicles then makes it possible to select the vehicles detected by a radar of the first vehicle to establish a communication beam per detected and connected vehicle which allows data communication between the first vehicle and each of these connected vehicles using the radar of the first vehicle for V2V communication.

Furthermore, the use of vehicle radar(s) to transmit or receive data in a V2V communication mode makes it possible to increase communication rates, the frequency band used by the radars being greater than that of the technology of ITS-G5 or DSRC, the maximum throughput permitted for data communication by radars therefore being much higher than that permitted for V2X or V2V communications of the ITS-G5 or DSRC type.

According to a variant, the method further comprises a step of transmitting data according to the V2V communication mode to each third vehicle selected via the communication beam specific to each third vehicle selected on the second frequency band.

According to another variant, the first information is included in a cooperative warning message type message, called a CAM message.

According to an additional variant, the radar being configured for object detection and for establishing at least one communication according to the V2V communication mode, the method further comprises the following steps:

- allocation of a lower part of a bandwidth on which the radar operates for object detection, the bandwidth being between 76 and 81 GHz and the lower part being between 76 and 79 GHz; And

- allocation of a high part of the bandwidth for the establishment of at least one V2V communication, the high part being between 79 and 81 GHz.

According to yet another variant, the radar being configured for object detection and for establishing at least one communication according to the V2V communication mode, the method further comprises the following steps:

- allocation of first time intervals of a bandwidth allocated to the radar for object detection;

- allocation of second temporal intervals of bandwidth for the establishment of at least one V2V communication.

According to an additional variant, the generation by spatial filtering comprises an adjustment of transmission and reception parameters of a set of radar antennas, the parameters comprising phase and/or amplitude parameters.

According to another variant, the position obtained from the first information and the position obtained from the second information are expressed in a marker associated with the first vehicle.

According to a second aspect, the present invention relates to a communication device for a vehicle embedding a millimeter wave radar system comprising at least one radar, the device comprising a memory associated with a processor configured for implementing the steps of the method according to the first aspect of the present invention.

According to a third aspect, the present invention relates to a vehicle communication system comprising the device as described above according to the second aspect of the present invention and a millimeter wave object detection radar system connected to the device such as described above according to the second aspect of the present invention.

According to a fourth aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the present invention or a system as described above according to the third aspect of the present invention.

According to a fifth aspect, the present invention relates to a computer program which comprises instructions adapted for the execution of the steps of the method according to the first aspect of the present invention, in particular when the computer program is executed by at least one processor.

Such a computer program can use any programming language, and be in the form of a source code, an object code, or an intermediate code between a source code and an object code, such as in partially compiled form, or in any other desirable form.

According to a sixth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for executing the steps of the method according to the first aspect of the present invention.

On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a ROM memory of the microelectronic circuit type, or even a magnetic recording means or a hard disk.

On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or terrestrial radio or by self-directed laser beam or by other ways. The computer program according to the present invention can in particular be downloaded onto an Internet type network.

Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in executing the method in question.

Brief description of the figures

Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting examples of embodiment of the present invention below, with reference to the attached Figures 1 to 3, in which:

schematically illustrates a communication environment for vehicles, according to a particular and non-limiting embodiment of the present invention;

schematically illustrates a communication device for a first vehicle of the , according to a particular and non-limiting embodiment of the present invention;

illustrates a flowchart of the different stages of a communication process for a first vehicle of the , according to a particular and non-limiting embodiment of the present invention.

Description of the implementation examples

A method and a communication device for a vehicle carrying a millimeter wave radar system will now be described in what follows with reference jointly to Figures 1 to 3. The same elements are identified with the same reference signs throughout of the description which follows.

According to a particular and non-limiting example of an embodiment of the present invention, a communication method implemented by a first vehicle carrying a millimeter wave radar system comprises the reception of first information representative of the position of each second vehicle of a set second vehicles (which includes one or more second vehicles).

This first information is received from each second vehicle, the first information being transmitted and received on a control channel on a first frequency band according to a vehicle-to-vehicle type communication mode, called V2V (from the English “Vehicle-to -Vehicle”). This first information is for example included in a CAM message broadcast by each second vehicle in V2V mode, for example in a frequency band around 5.9 GHz. This first information is used by the first vehicle to identify each second vehicle having transmitted this first information, for example via their respective positions, as corresponding to a connected vehicle, that is to say a vehicle configured to transmit and receive data in V2V via a wireless connection.

A set of third vehicles (including one or more third vehicles) is detected from second information obtained from a radar of the radar system of the first vehicle, which radar (like the other radars of the system) operates on a second band of frequencies higher than the first band. The second frequency band corresponds for example to the band between 76 and 81 GHz. The second information is advantageously representative of the position of each of the third vehicles detected.

One or more third vehicles in the set are selected by comparing their positions to those of the second vehicles. A third selected vehicle corresponds to one of the third vehicles whose position corresponds to that of one of the second identified vehicles.

Finally, a particular communication beam is generated by spatial filtering (beamforming) for each third vehicle selected, each generated beam originating from the radar having detected the set of third vehicles. Thus, there are as many beams generated as there are third vehicles selected, with a particular beam per third vehicle selected, the beam associated with a third vehicle spatially covering this third vehicle.

The use of position data received according to a V2V communication mode makes it possible to identify which vehicles in the environment of the first vehicle correspond to so-called connected vehicles, that is to say vehicles configured to communicate with the first vehicle. via a V2V wireless connection.

The identification of these connected vehicles then makes it possible to select the vehicles detected by a radar of the first vehicle to establish a communication beam per detected and connected vehicle which allows data communication between the first vehicle and each of these connected vehicles using the radar of the first vehicle for V2V communication.

There schematically illustrates an environment 1 for communication between vehicles, according to a particular and non-limiting embodiment of the present invention.

There illustrates an environment 1 comprising one or more roads and/or lanes on which a first vehicle 10 and one or more other vehicles 11, 12, 13 and 14 circulate.

According to the particular and non-limiting example of the , the vehicle 11 precedes for example the first vehicle 10 on the traffic lane of the first vehicle 10. The vehicle 12 travels on another traffic lane adjacent to that of the first vehicle 10, this adjacent lane being to the left of the traffic lane of the first vehicle 10 according to the direction of travel of the first vehicle 10. The vehicle 13 and the vehicle 14 travel on a lane adjacent to that of the first vehicle 10, this adjacent lane being to the right of the lane of the first vehicle 10 according to the direction of movement of the first vehicle.

The first vehicle 10 and at least part of the second vehicles 11 to 14 are advantageously configured to communicate using a so-called V2X communication mode, for example based on the 3GPP LTE-V or IEEE 802.11p standards of ITS G5. In such a V2X communication mode, each vehicle has a node to enable vehicle-to-vehicle V2V (vehicle-to-vehicle) and vehicle-to-vehicle-to-infrastructure (V2I) communication. -infrastructure") and/or vehicle-to-pedestrian V2P, the pedestrians being equipped with mobile devices (for example a smartphone) configured to communicate with vehicles.

According to the example of the , only vehicles 11, 12 and 13 correspond to so-called connected vehicles in that they are each configured to transmit and receive data via a wireless link according to a V2X communication mode, for example V2V. Vehicles 11 to 13 thus form a set of second vehicles, also called connected vehicles.

The first vehicle 11 and the second vehicles 11, 12, 13 form for example an ad hoc wireless network (also called WANET (from the English “Wireless Ad Hoc Network”) or MANET (from the English “Mobile Ad Hoc Network”). "), i.e. a decentralized wireless network. Unlike a centralized network which relies on an existing infrastructure including, for example, routers or access points linked together by a wired or wireless infrastructure, the ad hoc wireless network is made up of nodes which each participate in the routing data by retransmitting data from one node to another, from the sender to the receiver, depending on the network connectivity and the routing algorithm implemented. The ad hoc wireless network advantageously corresponds to an ad hoc vehicular network (or VANET, from the English “Vehicular Ad hoc NETwork”) or to an intelligent ad hoc vehicular network (or InVANET, from the English “Intelligent Vehicular Ad hoc NETwork"). In such a network, 2 or more vehicles each carrying a network node can communicate with each other as part of vehicle-to-vehicle (V2V) communication.

The first vehicle 10 is advantageously equipped with a millimeter wave radar system. The system comprises one or more radars, for example 1, 2, 4, 6, 8, 10 radars distributed over the first vehicle 10 to detect objects in the environment around the first vehicle 10. Each radar is adapted to emit waves electromagnetic and to receive the echoes of these waves returned by one or more objects, with the aim of detecting obstacles and their distances with respect to the first vehicle 10 for example. Each radar, or at least part of the plurality of radars, is further adapted to transmit and receive electromagnetic waves to communicate with another entity, for example one or more of the vehicles 11 to 14. A radar capable of both detecting objects and allowing radio communication with another entity is for example described in document WO2012/037680 A1, published on March 29, 2012. Such a radar comprises for example 2 modulators, 1 first modulator for generating waves for detecting objects and a second modulator for generating waves having suitable characteristics for carrying communication data. According to another example, each radar includes only one modulator and offers dual object detection/communication functionality by implementing a spread spectrum technique, for example direct sequence spread spectrum (or DSSS in English). , for “Direct-Sequence Spread Spectrum”), frequency hopping spread spectrum (or FHSS in English, for “Frequency-Hopping Spread Spectrum”) or even CDMA (from English “Code Division Multiple Access” or in French “Code division multiple access”). According to yet another example, the dual object detection/communication functionality is implemented by the use of the OFDM technique (from the English “Orthogonal Frequency-Division Multiplexing” or in French “Multiplexing by distribution of orthogonal frequencies").

The radars of the radar system of the first vehicle 10 are for example used as part of an automobile driving assistance system (ADAS in English, for “Advanced driver-assistance system”). Part of the radars is for example used for the detection of objects (other vehicles, obstacles, pedestrians for example) and another part of the radars for blind spot detection. The ADAS function(s) using data obtained from radars correspond for example to one or more of the following functions:

- object detection;

- vehicle detection in a blind spot;

- Parking assistance ;

- anti-collision;

- adaptive cruise control.

These ADAS functions are for example implemented by one or more dedicated computers. The data obtained from the radars on the basis of the waves generated by the radars are for example transmitted to this or these computers (via one or more data buses for example) for implementation of the ADAS functions.

Each radar operates for example in the frequency band around 77 GHz, for example in the 76-81 GHz band, according to standard EN 302 264.

A communication process between the first vehicle 10 on the one hand and one or more other vehicles 11, 12, 13 and/or 14 on the other hand is advantageously implemented by the first vehicle 10, that is to say by one or more processors of a computer or a combination of computers of the on-board system of the first vehicle 10, for example by the computer or computers in charge of controlling the radar system and/or a telematics control unit, called TCU (from the English “Telematic Control Unit”).

In a first operation, first information representative of the position of each second vehicle 11 to 13 of a set of second vehicles is received. This first information is for example transmitted by each second vehicle 11, 12, 13 on a control channel on a first frequency band according to a vehicle-to-vehicle type communication mode, called V2V.

According to the example of the , only vehicles 11 to 13 are configured to communicate in V2V, for example on the basis of technologies based on the IEEE 802.11p standard or even the technology on cellular networks called C-V2X.

The first information is for example transmitted by each second vehicle by means of a cooperative warning message type message, called CAM message (from the English “Cooperative Awareness Message” or in French “Cooperative Warning Message”). as defined in the technical specification ETSI TS 102 637-2 v1.2.1 of March 2011. Such CAM messages are for example broadcast (“broadcast”) at regular intervals by each of the nodes (second vehicles 11 to 13 ) periodically on a control channel, for example a CCH channel (from the English “Control Channel” or in French “Canal de commande”).

A CAM message carries a set of information about the second vehicle broadcasting it, including data on the kinematics of the second vehicle and its position. The position information included in the CAM message is defined in the world frame.

On receipt of the first position information, the first vehicle 10 applies for example a change of reference to determine the position of each second vehicle 11 to 13 in the reference associated with the first vehicle 10, such a reference having for example a point on the first vehicle 10 (for example the middle of the rear axle), a first axis corresponding to the longitudinal axis of the first vehicle 10 and a second axis corresponding to the transverse axis of the first vehicle 10, orthogonal to the first axis.

Such CAM messages are for example transmitted on the 5.9 GHz frequency band, for example in the frequencies between 5.850 and 5.925 GHz.

Receiving a CAM message transmitted by a second vehicle 11 to 13 allows the first vehicle 10 to determine the position of this second vehicle and also allows the first vehicle 10 to identify such a second vehicle as being a connected vehicle capable of communicating with the first vehicle in wireless connection according to the V2V communication mode.

In a second operation, a set of third vehicles 11 to 14 are determined by the first vehicle 10 from second information obtained from a radar 101 of the radar system of the first vehicle 10.

A vehicle in the environment of the first vehicle 10 detected by a radar 101 of the first vehicle 10 is called a third vehicle. The set of third vehicles includes one or more third vehicles. According to the particular example of the , the set of third vehicles includes 4 vehicles 11 to 14.

Object detection (for example a vehicle) by radar is based on the Doppler effect. For this purpose, electromagnetic waves are emitted by the radar, these waves being for example maintained with linear frequency modulation (FMCW or LMCW, from English “Frequency Modulated Continuous Wave” or “Linear Modulated Continuous Wave”), like this is classically the case for radars on board a vehicle. Such modulation makes it possible to obtain information on the distance and speed of the detected objects. Once generated at a determined frequency or frequency range, the waves are emitted for propagation in the air at a determined power and under specific radiation conditions. Once reflected by the detected object(s), the reflected waves (echo) are received by the radar for processing and analysis, in order to deduce useful information (distance of the detected object from the radar, speed of the detected object, azimuth of the detected object corresponding to the angle of incidence of the wave in a horizontal plane parallel to the plane of the roadway obtained by several antennas receiving the reflected waves, the azimuth being determined from the differences in phases between the reflected waves received).

The data thus obtained from the radar 101 having detected an object such as a third vehicle 11 to 14 makes it possible to determine a position of this third vehicle 11 to 14 detected with respect to the first vehicle 10 (i.e. a relative position). The relative position is for example determined from the distance information between the first vehicle 10 and the third vehicle detected, this distance information being obtained from the radar having detected the third vehicle.

The second position information of a third vehicle 11 to 14 is advantageously expressed in the local reference frame associated with the first vehicle 10.

In a third operation, all or some of the third vehicles detected by the radar are selected.

The selection of one or more third vehicles is advantageously obtained by comparing the position of each detected third vehicle 11 to 14 (obtained from the second information) with the positions of the second vehicles (obtained from the first information).

A third vehicle is selected when its position (obtained from radar 101) corresponds to a position of a second vehicle (obtained from the CAM message), which means that this third vehicle and this second vehicle correspond to one and the same vehicle.

Such a selection makes it possible to select among the vehicles detected by radar (i.e. the third vehicles) only those which are connected.

Thus, according to the particular example of the , only vehicles 11, 12 and 13 are selected from the set of third vehicles 11 to 14. The selected vehicles form a subset of the set of third vehicles, such a subset comprising for example between 1 and N vehicles, N corresponding to the number of vehicles detected by the radar (that is to say the number of vehicles included in the set of third vehicles 11 to 14).

In a fourth operation, a communication beam is generated for each third selected vehicle, the communication beam generated for a third vehicle spatially covering this third vehicle and being dedicated for data communications between the first vehicle 10 and this third vehicle.

All of the communication beams generated originate from the radar 101 having detected the third vehicles, these beams being generated according to the so-called spatial filtering method (beamforming). Such spatial filtering is known to those skilled in the art and carried out by combining the elements of a phased array antenna array in such a way that in particular directions, the Signals interfere constructively while in other directions the interference is destructive. Spatial filtering includes for example an adjustment of the transmission and reception parameters of a set of antennas of the radar 101, the parameters comprising phase and/or amplitude parameters. The radar 101 includes for example a plurality of transmitting antennas and a plurality of receiving antennas, which makes it possible to communicate data in V2V between these vehicles based on so-called MIMO technology (from the English “Multiple Input Multiple Output” or in French “Multiple inputs, multiple outputs”).

Thus, according to the example of the , a first communication beam 110 is generated for the third vehicle 11, this third beam 110 having its origin in the radar of the first vehicle 10 and spatially covering the third vehicle 11, and only the third vehicle 11.

A second communication beam 120 is generated for the third vehicle 12, this third beam 120 having its origin in the radar of the first vehicle 10 and spatially covering the third vehicle 12, and only the third vehicle 12.

A third communication beam 130 is generated for the third vehicle 13, this third beam 130 having its origin in the radar of the first vehicle 10 and spatially covering the third vehicle 13, and only the third vehicle 13.

No communication beam is generated for the vehicle 14 because the latter, even if it was detected by the radar of the first vehicle 10, does not correspond to a second vehicle, that is to say it does not is not considered to be a connected vehicle.

In a fifth operation, the first vehicle 10 transmits and/or receives data to and/or from one or more of the third selected vehicles 11 to 13 using the radar and the generated communications beams 110, 120, 130 according to a mode V2V communication, in the frequency band allocated to the radar (that is to say for example the band between 76 and 81 GHz).

The third vehicles 11 to 13 with which the first vehicle 10 is capable of communicating in V2V are also equipped with a radar system identical or similar to that of the first vehicle 10 and configured to emit and receive electromagnetic waves for data communication in V2V.

On the , as an illustrative example, the data communication between the first vehicle 10 and the third vehicle 11 via the beam 110 is implemented between the radar 101 of the first vehicle 10 and the radar 111 of the third vehicle 11, if applicable .

Data communication between the first vehicle 10 and the third vehicle 12 via the beam 120 is implemented between the radar 101 of the first vehicle 10 and the radar 121 of the third vehicle 12, if applicable.

Data communication between the first vehicle 10 and the third vehicle 13 via the beam 130 is implemented between the radar 101 of the first vehicle 10 and the radar 131 of the third vehicle 13, if applicable.

The electromagnetic waves transmitted for data transport according to the V2V communication mode are for example transmitted according to one of the following channel access methods:

- OFDMA, from English “Orthogonal Frequency Division Multiple Access” or in French “Access multiple à division enfrequency orthogonale”;

- TDMA, from English “Time Division Multiple Access” or in French “Access multiple à division dans le temps”;

- CDMA, from English “Code Division Multiple Access” or in French “Access multiple by division in code”.

According to a particular embodiment, the frequency band used by the radar 101 is divided in frequency between a first part and a second part. Thus, a lower part (the first part) of the bandwidth on which the radar operates is allocated for object detection (that is to say for the detection of third vehicles 11 to 13). In other words, a lower part of the frequency band used by a radar (i.e. the frequency band between 76 and 81 GHz) is allocated for the emission of waves for the detection of third vehicles. Such a low part of the frequency band is for example between 76 and 79 GHz.

An upper part (the second part) of the bandwidth on which the radar operates is allocated for V2V data communication, the upper part (or second part) being for example between 79 and 81 GHz.

According to this embodiment, the first part of the frequency band allocated to the radar 101 is reserved for object detection while the second part of the frequency band is allocated for data communication in V2V, for example according to the principle of OFDM (from the English “Orthogonal Frequency-Division Multiplexing” or in French “Multiplexing by distribution of orthogonal frequencies”).

According to another particular embodiment, the bandwidth allocated to the radar 101 is divided temporally for, on the one hand, the object detection function and, on the other hand, data communication in V2V mode.

Thus, first time intervals of the bandwidth allocated to the radar 101 are allocated for object detection and second time intervals of the bandwidth allocated to the radar 101 are allocated specifically for the establishment of V2V communications. The allocation of the first intervals and the second intervals is for example such that the first and second intervals alternate according to any pattern, for example so as to alternate a first time interval with a second time interval regularly.

The invention makes it possible to benefit from certain advantages of “beamforming” (for example more directivity in the transmission beams) by only generating communication beams for vehicles adapted to a V2V operating mode.

There schematically illustrates a device 2 configured to detect objects and communicate data, according to a particular and non-limiting embodiment of the present invention. The device 2 corresponds for example to a radar on board a vehicle, for example the first vehicle 10 and/or one or more third vehicles 11 to 13. According to a variant, the device 2 corresponds to a device on board the first vehicle 10, for example a computer in charge of controlling one or more radars of the radar system of the first vehicle 10

The device 2 is for example configured for the implementation of the operations described with regard to the and/or steps of the process described with regard to the . The elements of device 2, individually or in combination, can be integrated into a single integrated circuit, into several integrated circuits, and/or into discrete components. Device 2 can be produced in the form of electronic circuits or software (or computer) modules or even a combination of electronic circuits and software modules. According to different particular embodiments, the device 2 is coupled in communication with other devices (for example one or more UCE ("Electronic Control Unit" type calculators or in English ECU "Electronic Control Unit") of the on-board system of the vehicle) or similar systems, for example via a communications bus or through dedicated input/output ports.

The device 2 comprises one (or more) processor(s) 20 (or microcontrollers) configured to execute instructions for carrying out the steps of the method and/or for executing the instructions of the software(s) embedded in the device 2. The device 2 processor 20 may include integrated memory, an input/output interface, and various circuits known to those skilled in the art. The device 2 further comprises at least one memory 21 corresponding for example to a volatile and/or non-volatile memory and/or comprises a memory storage device which may comprise volatile and/or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

The computer code of the embedded software(s) comprising the instructions to be loaded and executed by the processor is for example stored on the first memory 21. The physical layer parameters for the generation and transmission of electromagnetic signals for the implementation of communications V2X and/or object detection in radar mode are also advantageously stored in memory 21. Memory 21 thus includes the signal reception parameters (modulation, coding, frame recurrence parameters for example) and the signal reception parameters. transmission (modulation, coding, frame recurrence parameters for example).

According to a particular and non-limiting embodiment, the device 2 comprises for example radio transmission means 24 configured for the emission of electromagnetic waves and radio reception means 25 configured to receive the echoes of the waves emitted by the means radio transmission 24 and/or to receive electromagnetic waves emitted by a remote radio device, for example a radar of a second vehicle.

According to a particular and non-limiting embodiment, the device 2 comprises an RF radio frequency interface 22, for example of the Bluetooth® or Wi-Fi®, LTE type (from the English “Long-Term Evolution” or in French “Evolution à long term"), LTE-Advanced (or in French LTE-advanced), ITS G5 based on IEEE 802.11p or a mobile network such as a 4G network (or LTE Advanced according to 3GPP release 10 – version 10) or 5G, in particular an LTE-V2X network, to communicate with external devices, for example another radar of another vehicle or communication equipment such as a relay antenna or roadside unit (UBR).

According to another particular embodiment, the device 2 comprises a communication interface 23 which makes it possible to establish communication with other devices, such as for example one or more UCE type calculators or other radars of the radar system of the vehicle via a communication channel 230. The communication interface 23 corresponds for example to a transmitter configured to transmit and receive information and/or data via the communication channel 230. The communication interface 23 corresponds for example to a wired network of the CAN type (from the English “Controller Area Network” or in French “Réseau de controllers”) or CAN FD (from the English “Controller Area Network Flexible Data-Rate” or in French “Réseau de controllers à flexible data rate").

According to an additional particular embodiment, the device 2 can provide output signals to one or more external devices, such as a display screen and/or other peripherals via respectively output interfaces not shown.

There illustrates a flowchart of the different stages of a communication method implemented by a vehicle carrying a radar system comprising at least one millimeter wave radar, according to a particular and non-limiting embodiment of the present invention. The method is for example implemented by a device on board the first vehicle 10, for example the device 2 of the .

In a first step 31, first information representative of the position of each second vehicle of a set of second vehicles is received, the first information being transmitted by each second vehicle on a control channel on a first frequency band according to a mode of vehicle-to-vehicle type communication, known as V2V.

In a second step 32, a set of third vehicles is detected from second information obtained from a radar of the radar system operating on a second frequency band higher than the first frequency band, the second information being representative of the position of the vehicle. every third vehicle.

In a third step 33, at least part of the set of third vehicles is selected by comparing the positions of the second vehicles with the positions of the third vehicles, the at least part of the set of third vehicles comprising each third vehicle of the set of third vehicles having as position a position of a second vehicle.

In a fourth step 34, a communication beam particular to each third selected vehicle is generated by spatial filtering, each communication beam originating from the radar and spatially covering a single third selected vehicle.

According to a variant, the variants and examples of the operations described in relation to the apply to the stages of the process of .

Of course, the present invention is not limited to the exemplary embodiments described above but extends to a method of controlling a radar system used for the detection of objects and for communications, for example of the V2X type. or V2V, and embedded on a vehicle, and to the device configured for the implementation of such a method.

The invention also relates to a vehicle, for example an automobile or more generally a land motor vehicle, comprising the device 2 of the .

Claims (10)

Communication method for a first vehicle (10), said first vehicle (10) carrying a millimeter wave radar system, said method comprising the following steps:
- reception (31) of first information representative of the position of each second vehicle (11 to 13) of a set of second vehicles, said first information being transmitted by each second vehicle (11 to 13) on a control channel on a first frequency band according to a vehicle-to-vehicle type communication mode, called V2V;
- detection (32) of a set of third vehicles (11 to 14) from second information obtained from a radar (101) of said radar system operating on a second frequency band higher than said first frequency band, said second information being representative of the position of each third vehicle;
- selection (33) of at least one part (11 to 13) of the set of third vehicles (11 to 14) by comparison of the positions of the second vehicles with the positions of the third vehicles, said at least part of the set of third vehicles comprising each third vehicle of the set of third vehicles having as position a position of a second vehicle;
said method further comprising the following step for each third selected vehicle (11 to 13):
- generation (34), by spatial filtering, of a communication beam (110, 120, 130) particular to said each third selected vehicle (11, 12, 13), each communication beam having as its origin said radar (101) and spatially covering a single third selected vehicle. Method according to claim 1, further comprising a step of transmitting data according to said V2V communication mode to said each third selected vehicle (11, 12, 13) via the particular communication beam (110, 120, 130) to said each third vehicle selected on said second frequency band. Method according to claim 1 or 2, for which said first information is included in a cooperative warning message type message, called CAM message. Method according to one of claims 1 to 3, for which, said radar (101) being configured for object detection and for establishing at least one communication according to said V2V communication mode, said method further comprises the following steps :
- allocation of a lower part of a bandwidth on which said radar (101) operates for said object detection, said bandwidth being between 76 and 81 GHz and said lower part being between 76 and 79 GHz; And
- allocation of a high part of said bandwidth for the establishment of said at least one V2V communication, said high part being between 79 and 81 GHz. Method according to one of claims 1 to 3, for which, said radar (101) being configured for object detection and for establishing at least one communication according to said V2V communication mode, said method further comprises the following steps :
- allocation of first time intervals of a bandwidth allocated to said radar (101) for said object detection;
- allocation of second time intervals of said bandwidth for the establishment of said at least one V2V communication. Method according to one of claims 1 to 5, for which said generation by spatial filtering comprises an adjustment of transmission and reception parameters of a set of antennas of said radar (101), said parameters comprising phase parameters and /or amplitude. Method according to one of claims 1 to 6, for which the position obtained from said first information and said position obtained from said second information are expressed in a marker associated with said first vehicle (10). Computer program comprising instructions for implementing the method according to any one of the preceding claims, when these instructions are executed by a processor. Communication device (2) for a vehicle carrying a millimeter wave radar system comprising at least one radar, said device (2) comprising a memory (21) associated with at least one processor (20) configured for implementing the steps of the process according to any one of claims 1 to 7. Vehicle (10) comprising the device (2) according to claim 9.